@mixin size($w: 100%, $h: 100%) {
    width: $w;
    height: $h;
}

@mixin height($h) {
    height: $h;
    line-height: $h;
}

@mixin position ($left: 0, $top: 0) {
    position: absolute;
    left: $left;
    top: $top;
}

@mixin transition($time: 0.5s){
    transition:$time;
}

@mixin cricle($w) {
    @include size($w, $w);
    border-radius: 50%;
}
//居中定位
@mixin middlePos{
    position: absolute;
    left: 0;
    top: 0;
    transform: translate(-50%, -50%);
}

//文字溢出省略号
@mixin ellipsis {
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
}